It’s uncommon for the US Defense Department to be moved by North Korean rhetoric and war-mongering, but the recent escalation of threats has succeeded in eliciting a response from the Pentagon.

The US announced over the weekend that it is bolstering its nuclear missile defences in Alaska and Japan in response to the threat from North Korea. The Defense Department plans to increase missile defence systems in Alaska, adding 14 interceptor missiles. The US will also be installing a second X-band radar system in Japan to improve its early warning capabilities.

The US is going to this expense (roughly a billion dollars) because, it admits, the North Korean missile program is more advanced than first thought. While Pyongyang is likely still years away from developing a genuine inter-continental ballistic missile, the US wants to be prepared for any contingency. In fact, there are experts on North Korea such as Victor Cha, a former Director for Asian Affairs in the White House, who say that North Korea poses a near-term rather than long-term threat. So, just how great is the threat from North Korea and can the US and its allies minimise it?

But this is all just posturing. North Korea doesn’t want to go to war. Its preferred position is to continue to demonise the US and convince its population that it must fend off enemies at the gates—bolstering support for the regime, and allowing it to continue funnelling resources to the military.

The North can only step up its rhetoric so much before it finds that it has nothing left to threaten. In the meantime, the country will feel the impact of the latest round of UN Security Council sanctions. As my colleague Tanya Ogilvie-White said recently, sanctions have slowed the progression of the country’s nuclear program, and they do limit its economic growth. However, for greatest effect, sanctions should be teamed with a policy of engagement. The North has proven resilient against a sanctions only policy in the past (it has been under some form of sanction, on and off, for the last seven decades (PDF)) and sanctions also back the regime into a corner; acquiescence would mean losing face domestically.

The US has chosen to use sanctions to punish the regime and doesn’t want to reward its bad behaviour by granting it an audience. But if the US is serious about reducing the threat of North Korea, it’s likely to get a better result if it teams sanctions with engagement.

The North Korean regime is guilty of horrific human rights abuses. It presents a danger to the region and, by exporting nuclear materials and technology, to the wider international community. But the regime won’t be toppled by an ‘Arab Spring’-like event in the near future. This means that the US must deal with Kim Jong-un.

If the US continues to respond to the North Korean threat with all sticks and no carrots it could worsen the situation. Beijing has criticised the US, saying the deployment will ‘intensify antagonism’. But Xi Jinping will be more concerned about whether missile defence upgrades could threaten China’s credible second strike capability, putting pressure on it to expand its nuclear arsenal in response. If the US wants a greater influence over North Korea, it should (dare I say it) take Rodman’s advice and call Kim Jong-un. More positive incentives will give the US and its allies more leverage in dealing with North Korea, and are more likely to defuse tensions in North East Asia.